E. Day et Gm. Branch, Relationships between recruits of abalone Haliotis midae, encrusting corallines and the sea urchin Parechinus angulosus, S AFR J MAR, 22, 2000, pp. 137-144
Citations number
32
Categorie Soggetti
Aquatic Sciences
Journal title
SOUTH AFRICAN JOURNAL OF MARINE SCIENCE-SUID-AFRIKAANSE TYDSKRIF VIR SEEWETENSKAP
In kelp beds of the South-Western Cape. South Africa, a strong positive rel
ationship exists between the sea urchin Parechinus angulosus and juveniles
of the abalone Haliotis midae. Field surveys reported here revealed a posit
ive, but weak, association between this urchin and H. midae recruits (i.e.
individuals <3 mm shell length). Selectivity indices showed that recruits o
ccurred exclusively on encrusting coralline algae and showed preferences fo
r strongly textured corallines. rather than those with smooth texture. On s
mooth corallines, around 80% of recruits were under urchins, compared with
about 25% on textured corallines, suggesting that any need for shelter bene
ath urchins is greatest on smooth surfaces.